1Make Them Improper
234 = 114(2 × 4 + 3 = 11)
113 = 43(1 × 3 + 1 = 4)
Whole numbers hide pieces. Turn every whole into pieces before you subtract.
2Find the LCD
4: 4 8 12 16 20
3: 3 6 9 12 15
first match = 12 → twelfths
List multiples of each denominator. The first shared one is the least common denominator.
3Rename Both
114 × 3 top and bottom = 3312
43 × 4 top and bottom = 1612
Multiplying top and bottom by the same number changes the name, never the amount.
4Subtract & Simplify
3312 − 1612 = 1712
= 1 5/12
Twelfths minus twelfths: 33 − 16 = 17. Then pull the whole back out: 17 twelfths = 1 and 5 twelfths.
